Great Barrier Reef Microbial Genomes Database constructed via hybrid Nanopore and Illumina sequencing (nature.com)

• Hybrid assembly yielded 29-fold higher contiguity (N50 730 vs 25 kb) and doubled number of medium-to-high quality prokaryotic MAGs per sample.
• Standard short-read assemblies missed dominant marine lineages due to strain heterogeneity (nucleotide diversity >0.02) and GC bias (<40% GC).
• GBR-MGD includes 808,585 viral genomes, with a newly described marine clade of Crassvirales, and 20 chromosome-level picoeukaryote genomes for Bathycoccus and Ostreococcus.
• Microbial community composition distinguished no-take marine reserves (NTMRs) from fished reefs with 74.6% accuracy, with NTMRs enriched in streamlined, low-GC oligotrophic taxa.

"Researchers present the Great Barrier Reef Microbial Genomes Database (GBR-MGD), comprising 5,283 prokaryotic, 808,585 viral, and 20 chromosome-level picoeukaryote genomes from seawater samples. Hybrid long-read (Nanopore) and short-read (Illumina) sequencing recovered previously underrepresented lineages such as Pelagibacter and Prochlorococcus that are missed by short-read-only assemblies due to strain heterogeneity and GC bias. The database enabled identification of microbial indicator taxa that predict reef protection zoning with ~74% accuracy, demonstrating utility for ecosystem management."